Core spacer for differential winding machine



y 30, 1967 N. G. DALES ETAL 3,322,359

CORE SPACER FOR DIFFERENTIAL WINDING MACHINE Filed Jan. 11, 1965 2 Sheets-Sheet 1 FIG.2 H63 INVENTORS ATTORNEY y 1967 N. G. DALES ETAL 3,322,359

NTIAL WINDING MACHINE CORE SPACER FOR DIFFERE Filed Jan.

2 Sheets-Sheet 2 FIG. 7

F l G. 8

K INVENTORS NICHOLAS e. DALES BY ROGER w.

v ATTORNEY United States Patent Ofitice 3,322,359 Patented May 30, 1967 3,322,359 CORE SPACER FOR DIFFERENTIAL WINDING MACHINE Nicholas G. Dales, Scarsdale, NY., and Roger W. Young,

Montclair, N.J., assignors to John Dusenbery Company, Inc., Clifton, NJ, a corporation of New Jersey Filed Jan. 11, 1965, Ser. No. 424,562 2 Claims. (Cl. 242-68) This invention relates to improvements in core spacers for use on web slitting and rewinding machines.

In slitting and rewinding machines, of the class to which this invention is directed, a relatively wide web is cut to desired narrower strips, which strips are then rewound into roll form on individual cores mounted on a positively driven shaft, or mandrel. In order to insure a smooth rewinding of the cut strips, a certain amount of tension must be maintained on each individual strip during the rewinding operation. This is accomplished by rotating the mandrel at a higher speed than the cores, such arrangement being referred to in this art as differential winding. As the diameter of the rewound rolls increases, the rotation thereof decreases since the strips are fed to the rewind rolls from a constant speed pull roll. Accordingly, arrangements are provided to afford slippage between the rewind cores and the supporting mandrel, which slippage increases automatically as the diameter of the rewound roll increases.

A variable factor which effects the rewinding of the cut strips is the normal variation in gauge, or thickness of the particular web. This results in the diameter of some rewound rolls increasing at a faster rate than others, and, consequently, this factor cannot be compensated for by adjustment of the speed of the common mandrel. To overcome this problem, it is the practice to provide an arrangement wherein each core can slip on the mandrel in correspondence with the tension of the associated strip and independently of the other cores. This is done by inserting core spacer rings over the mandrel and between each rewind core. These core spacer rings are individually keyed to the supporting mandrel and the assembly of spacer rings and cores is clamped, axially, by suitable loading means carried at the ends of the mandrel. Thus, the core spacers are positively driven by the mandrel while each core is free to slip relative to the mandrel as the tension of the associated strip exceeds the frictional restraining force exerted against the ends of the core by the adjacent core spacers.

Normally, a winding machine is provided with two rewind mandrels axially displaced relative to each other with each mandrel carrying a plurality of rewind cores. Adjacently-disposed strips of the slit web are directed to dilferent mandrels so that the spacing of the cores on each mandrel is equal to the width of the strips. Such spacing is maintained by the core spacers which are clamped against the ends of the cores to provide a predetermined amount of restraining friction.

After the rewind coils have been wound to a desired diameter, it is, of course, necessary to remove the coils and core spacers from the supporting mandrel, after Which the spacers and new cores must be loaded, manually, in alternate relation on the mandrel. Such hand loading requires a significant amount of time, during which the machine is shut down, particularly since each core spacer must be oriented so that its key is disposed in the axial keyway formed in the mandrel. Various loading arrangements have been proposed to facilitate reloading of the mandrels. Generally, these consist of a fixture into which cores and core spacers can be placed in proper axial alignment. A mandrel then is slidably inserted through the alternate cores and spacers. These arrangements reduce the time during which the machine must be shut down, as the described loading can be done on a separate mandrel within the time required for one rewinding cycle of the machine. However, even these arrangements leave something to be desired in that it is necessary for the loader to rotate the mandrel, as it is slidably inserted into the axially aligned cores and spacers, in order that the key of each core spacer passes into the mandrel keyway. Alternatively, each core spacer must be rotated relative to the mandrel to effect the proper .keying of the spacer on the mandrel. Additionally, core spacers, as presently made, are expensive as the key of each core is integral therewith and is formed by a machining operation.

An object of this invention is the provision of a core spacer for use on differential rewinding machines, which core spacer is of simple, economical construction.

An object of this invention is the provision of a core spacer adapter for mechanically coupling to a mandrel having an axial keyway formed therein, said core spacer being provided with a spring-biased key whereby a plurality of such core spacers can be loaded on the mandrel in a minimum of time.

An object of this invention is the provision of a core spacer and mandrel combination for use on differential rewinding machines, said mandrel having a tapered end and an axial keyway formed therein and said core spacer having a plurality of spring-biased keys, the arrangement being such that insertion of the mandrel through the spacer causes a radial displacement of those keys which are not in axial alignment with the mandrel keyway.

These and other objects and advantages will become apparent from the following description when taken with the accompanying drawings showing several embodiments of the invention. It will be understood, however, that the drawings are for purposes of illustration and are not to be construed as defining the scope or limits of the invention, reference being had for the latter purpose to the claims appended hereto.

In the drawings wherein like reference characters denote like parts in the several views:

FIGURE 1 is a fragmentary, isometric view showing rewind cores .and core spacers as incorporated in a differential rewinding machine;

FIGURE 2 is a side elevational view of a core spacer made in accordance with one embodiment of this invention;

FIGURE 3 is a cross-sectional view taken along the line III-III of FIGURE 2;

FIGURE 4 is a side elevational view of a core spacer made in accordance with another embodiment of this invention;

FIGURE 5 is a cross-sectional view taken along line VV of FIGURE 4;

FIGURE 6 is a side elevational view of a core spacer made in accordance with still another embodiment of this invention;

FIGURE 7 is a cross-sectional view taken along the line VII-VII of FIGURE 6; and

FIGURE 8 is a fragmentary, isometric view of a mandrel made in accordance with this invention.

Reference, now, is made to FIGURE 1, wherein there is shown a rewind mandrel 10 spaced from and parallel to a pull roll 11. The pull roll is coupled to the main drive of the machine and rotates at a constant speed and the mandrel is driven by a mechancial drive at a speed suflicient to keep pace with the pull roll at the start of the winding operation. Rewind cores 12, generally made of cardboard, are freely rotatable on the mandrel and are spaced apart a distance equal to the width of the cut strips 13 by core spacers 14. Each core spacer is provided with a key which extends into an axial keyway 15 formed in the mandrel. Such keys slide freely in the mandrel keyway while preventing rotation of the spacers relative to the mandrel. A predetermined pressure is applied, axially, to the assembly of cores and core spacers by suitable means carried at the ends of the mandrel, such means being well known in the art and not shown in the drawings. Thus, the core spacers are positively driven by the mandrel while each of the rewind cores 12 obtains a driving torque from the frictional contact between the core ends and the spacers. Since each rewind core is frictionally driven, the slippage between the cores and the mandrel increases as the diameter of the rewound coil of the strip material increases.

Normally, the web which is cut into a plurality of strips 13 varies in thickness whereby the increase in the diameter of some rewound coils increases at a faster rate than others. This would result in unequal tensions on the rewound rolls if all of the cores were forced to rotate at the same speed. However, since each of the rewound cores 12 is independently rotatable about the mandrel, such variations in the tensions of the strips is compensated for by a corresponding variation in the slippage of the cores relative to the mandrel.

A second mandrel spaced from the mandrel and associated with a second pull roll carries a similar assembly of rewind cores and spacers for Winding the alternate cut strips lying adjacent to the illustrated strips 13 at the cutting station of the machine. Heretofore, the radial key of each core spacer has been in the form of a rivet head, which is expensive. More important is the fact that in such prior core spacers the key is securely fixed to the body of the spacer. Hence, in order to load a plurality of such spacers "on a single mandrel, it is necessary for the loader to orient the key of each spacer with the mandrel keyway.

Core spacers made in accordance with this invention are provided with one or more radially-displace-able keys and the mandrel is provided with a tapered end, thereby facilitating the loading of the spacers on the mandrel.

FIGURES 2 and 3 illustrate a metal core spacer 16 made in accordance with one embodiment of this invention. The key comprises a metal plug 17 having an integral flange formed intermediate the ends thereof. One end of the plug passes through a radial clearance hole formed in the spacer wall and the other end extends through a clearance hole formed in a leaf spring 18, said leaf spring having an end secured to the spacer, as by a screw 19.

In the embodiment shown in FIGURES 4 and 5, two diametrically-opposite radial holes are formed in the wall of the core spacer 20. A wire spring 21, formed to conform generally to the outer surface of the spacer, has its ends offset and passing through the clearance holes formed in the spacer walls. The protruding ends of the spring constitute two keys, either one of which may be disposed in the axial keyway of a mandrel. It will be apparent that when a mandrel, having a diameter somewhat less than the internal diameter of the spacer, is inserted through the spacer, one of the spring ends will engage the surface of the mandrel when the other spring end extends into the keyway. Such radial expansion of the spring at one end results, effectively, in an increase of pressure applied to the other spring end, thereby maintaining such other end firmly in the mandrel keyway.

Another embodiment of the invention is shown in FIGURES 6 and 7. Here, there are two wire springs 23 and 24 having offset ends passing through radial clearance holes formed in the wall of the spacer 24. In this case, the ends of the springs are bent back to form loops, Which loops constitute the keys for coupling the spacer to the mandrel. It may here be pointed out that the core spacers have a relatively thick wall so as to provide a fairly large area of mutual contact with the ends of adjacent rewind cores in order to provide sufficient frictional restraining force fOr the cores without requiring the application of an unduly large axial unit pressure thereto. Thus, when the core spacer 24 is mounted on a mandrel having a single axial keyway, three of the spring loops will abut the surface of the mandrel when the fourth spring loop is disposed within the keyway. The thick wall of the spacer, together with the angular disposition of the adjacent radial holes formed therein, prevents a separation of the springs from the mandrel during the mandrel loading operation and during machine operation.

FIGURE 8 is a fragmentary isometric view of a mandrel 10' adapted for use with core spacers made in accordance with this invention. Such mandrel, made of hardened steel, has a single, conventional, axial keyway 25 and is provided with a tapered end. The rewind cores and core spacers are alternately loaded on the mandrel form the tapered end. When the tapered end of the mandrel is inserted into the core spacer, the single, or multiple keys of the core spacer which are not aligned with the mandrel keyway will be engaged by the tapered mandrel end and displaced radially. Thereafter, such key, or keys, will ride on the mandrel surface until either the spacer or the mandrel is rotated to bring a key into alignment with the mandrel keyway. Such key, being spring-biased, will then snap into the keyway, thereby coupling the spacer and mandrel for simultaneous rotation. Actually, the radial pressure applied to the key, or keys, of the particular core spacer by the associated spring need only be SLll'fiClfiIlt to retain the key within the keyway of the mandrel. This minimizes marring of the mandrel surface upon relative rotation of the mandrel and core spacers to effect the described alignment of a key with the mandrel keyway. Actually, a plurality of core spacers may be loaded on the mandrel, alternately with the rewind cores, and without consideration to the alignment of the spacer keys with the keyway of the mandrel. Such assembly is then pressed together, axially, by conventional clamping means carried by the mandrel, to provide a predetermined amount of frictional pressure between the cores and the spacers. The so-loaded mandrel is placed into position on the machine and coupled to the drive shaft. The end of each cut strip is fastened to the associated rewind core, as by a piece of adhesive tape, and the machine placed into operation. With respect to those core spacers which are not locked to the mandrel by their respective key, these spacers will slip on the mandrel until the key snaps into the mandrel keyway. In the case of a core spacer constructed as shown in FIGURES 2 and 3, the maximum angular extent of such spacer slippage is somewhat less than 360 degrees, whereas with a core constructed as shown in FIGURES 6 and 7, the maximum spacer slippage will be somewhat less than degrees. In any event, within less than one revolution of the mandrel, all of the spacers are locked to the mandrel and thereafter the individual rewind cores will slip on the mandrel in proportion to the increase in the diameter of the rewound roll.

While we have shown various constructions of the core spacer wherein the spring-biased keys are positioned in a transverse plane which bisects the spacer, it will be apparent that two or more spaced and axially-aligned keys may be provided on a given core spacer. For example, in the single spring key arrangement shown in FIG- URES 4 and 5, and in a core spacer having a relatively long axial length, two such springs may be carried by the spacer proximate to the ends thereof.

Having now described several embodiments of our invention, those skilled in this art will be able to make various changes and modifications without thereby departing from the scope and spirit of the invention as recited in the following claims.

We claim:

1. For use on a differential rewinding machine, the combination of a core spacer having a radial hole extending through the wall thereof, a key slidably disposed in said hole, spring means normally biasing the key so that 5 an end thereof extends beyond the inner wall of the spacer, and a mandrel having an axial keyway formed therein, said mandrel having a tapered end which engages the end of said key as the mandrel is inserted through the core spacer, said key thereafter engaging said keyway to couple said spacer to said mandrel.

2. For use on a differential Winding machine the combination of,

(a) a cylindrical core spacer having a plurality of radial holes extending through the Wall thereof,

(b) spring means carried by the core spacer and having offset ends extending through the said holes, said ends terminating substantially on a circle having a diameter significantly less than the inside diameter of said spacer, and

(c) a mandrel having an axial keyway formed therein, said mandrel having an outside diameter greater than that of the said circle, but less than the inside diameter References Cited 10 UNITED STATES PATENTS 1,261,871 4/1918 Thomas 24268 2,270,806 1/1942 Johnson 242-68 X 2,533,307 1'2/1'950 Amos et a1 24275.5

a FRANK I. COHEN, Primary Examiner.

GEORGE F. MAUTZ, Examiner. 

1. FOR USE ON A DIFFERENTIAL REWINDING MACHINE, THE COMBINATION OF A CORE SPACER HAVING A RADIAL HOLE EXTENDING THROUGH THE WALL THEREOF, A KEY SLIDABLY DISPOSED IN SAID HOLE, SPRING MEANS NORMALLY BIASING THE KEY SO THAT AN END THEREOF EXTENDS BEYOND THE INNER WALL OF THE SPACER, AND A MANDREL HAVING AN AXIAL KEYWAY FORMED THEREIN, SAID MANDREL HAVING A TAPERED END WHICH ENGAGES THE END OF SAID KEY AS THE MANDREL IS INSERTED THROUGH THE CORE SPACER, SAID KEY THEREAFTER ENGAGING SAID KEYWAY TO COUPLE SAID SPACER TO SAID MANDREL. 